Dark Fire — Angela Dorsey

When Lisa's family was forced to sell their house and horses, life became hard enough - but then her dad finds out Lisa is going everyday to visit the horse that was once hers, her beloved Jupiter, and forbids her to go again. But nothing is going to stop Lisa, not even the new owner's nephew who threatens her. And now the final blow, the nephew is abusing Jupiter! Lisa feels helpless and outnumbered. Only one thing is for certain: she will not abandon the horse she loves. She just has to find a way to solve all the problems. And then the very bad situation becomes infinitely worse.